The FIG. 1 shows a structure of a prior suspension assembly 1. The suspension assembly 1 includes a mount plate 2, a load beam 3, a flexure 4 and a slider 5. The mount plate 2 has an aperture 8 provided on one end, through which a shaft 11 (FIG. 2) fixed on a frame of the hard disk drive device is fitted for rotatably positioning the plate 2. One end of the load beam 3 is fixed on the other end of the mount, plate 2. The load beam 3 can flexibly bend at a hinge portion 7. The flexure 4 is attached on a lower surface of the load beam 3, and includes an extended member 9. The slider 5 including a read/write head is supported on the member 9, which provides a gimbal type supporting mechanism for the read/write head. The read/write head is mounted on a lower surface of the slider 5, and writes the data to a magnetic recording disk 10 (FIG. 2) or reads the data from the disk 10.
The small size hard disk drive device has been used as a memory of a portable personal computer. The thickness of the mount plate 2, the load beam 3 and the flexure 4 of the suspension assembly made of stainless steel has been made thinner to allow more disks to be configured on a spindle and to increase the storage capacity of the hard disk device.
A problem resulting from thinning the suspension assembly 1 is that, with left end of the suspension assembly 1 being mounted on the shaft 11 on the frame and with the slider 5 and the head at the right end thereof being landed on the surface of the magnetic recording disk 10, the suspension assembly 1 is entirely bent from its normal position 12 toward the magnetic recording disk 10 when an unexpected shock is applied to the personal computer, as shown in the FIG. 2. A sharp edge of the load beam 3 or a sharp edge of the flexure 4 contacts or collides with the surface of the magnetic recording disk 10, resulting in damage of its surface, so that a desired read/write operation is not performed.
The FIGS. 3(A), (B) and (C) show the movement of the portion of the load beam 3 taken along the line A--A in the FIG. 2. The FIG. 3(A) shows a parallel mode in which the load beam 3 is moved in parallel from its normal position 12 to the disk 10. The FIGS. 3(B) and (C) show a twist mode in which the load beam 3 is twisted in the movement towards the disk 10, and the surface of the magnetic recording disk 10 is damaged by the right side edge 13 or the left side edge 14. The inventors of the present invention have found that the most of the damage is caused by the movement of the twist mode in the FIGS. 3(B) and (C).